1. Field of the Invention
The present invention is in the field of method and apparatus for cleaning internal structures and components of an automotive engine. More particularly, the present apparatus relates to a method and apparatus for cleaning the intake system, including the intake plenum, runners, and ports; and intake valves and combustion chambers of an automotive engine while the engine is assembled and running.
2. Related Technology
The cleaning of carburetors, intake systems, intake valves and combustion chambers of assembled automotive engines (i.e., without requiring disassembly of the engine) has been an objective for mechanics and the operators of automobiles almost from the beginning of the automobile itself. Carburetor cleaning spray aerosol products are very common, and are generally dispensed into the air intake of a carburetor on an engine while the engine is running. These products provide a spray of the cleaning liquid, which the user generally directs to the most soiled areas of the carburetor while applying the spray into the running engine. With products of this nature, the combination of a relatively slow rate of introduction of the liquid cleaner, and the structures of the carburetor itself against which the spray is directed (tending to break up the spray into droplets), generally prevent the accumulation of liquid in the intake system of the engine.
Other engine cleaning products of this nature have been developed in recent years which are introduced into the intake system of an automotive engine while it is running, and which are introduced via a vacuum fitting of the engine, for example. These products are generally supplied in liquid non-aerosol form, and are introduced into the running engine in liquid form using engine vacuum to draw the product into the engine. These newer products are generally more effective at cleaning an engine than the older conventional and aerosol products, but also have a problem in that distribution of the cleaning product among the several intake runners, intake ports, intake valves and combustion chambers of a multi-cylinder engine is not uniform. In other words, some of the cylinders of an engine cleaned in this way may receive an excess of the cleaning product, while other cylinders of the engine receive less of the cleaner, or virtually none at all. Understandably, an engine will not be cleaned satisfactorily if a liquid cleaner product is not distributed with a substantial degree of uniformity within the intake system and among the cylinders of the engine.
Further, a problem with some automotive engines is that the cleaner is introduced at a rate sufficient in some cases to cause liquid puddling in the intake systems of the engines. Generally, these engine cleaning products are introduced in liquid form by engine intake manifold vacuum, which draws the liquid from a dispensing container via a connecting hose or conduit. A metering orifice may be disposed in the liquid flow path to limit the rate at which the cleaning liquid is drawn into the engine by engine vacuum. Moreover, in most engine designs these newer cleaning products cause no problem because the cleaner is broken up into droplets, and is drawn into the combustion chambers of the engine without accumulating to any large extent. However, some engine designs, for example, those with an intake manifold floor or plenum floor which at least in part is lower than the intake valves of the engine can experience difficulty with such engine cleaner products. That is, a persistent problem with some designs of automobile engines when such products are used has been the puddling of cleaning liquid in the intake manifold of the engine. In other words, some engine designs are such that the intake manifold offers low areas or recesses where significant quantities of cleaning liquid can accumulate even though the liquid is introduced while the engine is running.
Further, the air flow in the intake system of an engine while idling or at a speed slightly above idle (which is ordinarily the case while the cleaner is being introduced) is generally not sufficient to either move the puddled liquid to a combustion chamber, or to vaporize the liquid. This problem may be worsened if the engine is not properly warmed up prior to use of the cleaner. In such cases, the intake manifold is cool, and the liquid cleaner is not as readily vaporized.
In cases resulting in puddling of the cleaning liquid in the intake manifold of an engine, subsequent racing of the engine or moving of the automobile, for example can result in liquid from the puddle being sloshed or drawn by engine air flow into one or more of the combustion chambers of the engine while it is running. In such an event, if a quantity of liquid cleaner is drawn into a combustion chamber and is sufficient to completely fill the clearance volume of the chamber, hydraulic locking of the engine results. That is, serious damage to the engine can result when a piston of the running engine approaches the engine head and is blocked by a quantity of essentially incompressible liquid. Operation of the running engine is then brought suddenly to a stop, with possible internal damage to the engine.
In view of the above, it would be desirable to provide a method and apparatus for introducing a liquid cleaner into the intake system of an automotive engine while it is running, and while reducing or eliminating the possibility for the liquid leaner to puddle in the intake system of the engine.